Re: [Ocfs2-devel] [RFC] Should we revert commit "ocfs2: take inode lock in ocfs2_iop_set/get_acl()"? or other ideas?
Hi Eric,
I've added linux-fsdevel to the cc list as this should get a bit
broader attention.
On Wed, Oct 19, 2016 at 01:19:40PM +0800, Eric Ren wrote:
> Mostly, we can avoid recursive locking by writing code carefully. However, as
> the deadlock issues have proved out, it's very hard to handle the routines
> that are called directly by vfs. For instance:
>
> const struct inode_operations ocfs2_file_iops = {
> .permission = ocfs2_permission,
> .get_acl= ocfs2_iop_get_acl,
> .set_acl= ocfs2_iop_set_acl,
> };
>
>
> ocfs2_permission() and ocfs2_iop_get/set_acl() both call ocfs2_inode_lock().
> The problem is that the call chain of ocfs2_permission() includes *_acl().
What do you actually protect in ocfs2_permission? It's a trivial
wrapper around generic_permission which just looks at the VFS inode.
I think the right fix is to remove ocfs2_permission entirely and use
the default VFS implementation. That both solves your locking problem,
and it will also get you RCU lookup instead of dropping out of
RCU mode all the time.
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Re: [Ocfs2-devel] BUG_ON(le64_to_cpu(fe->i_size) != i_size_read(inode)) is triggered in ocfs2_truncate_file()
Hi Zhen,
This should be file system consistency issue between inode in memory and inode
in disk,
You should look at the code that modify the file size in memory, and then
whether the code also sync the change to the disk.
Thanks
Gang
>>>
> Hi all,
>
> Any one ever see this BUG_ON() assertion
> (https://github.com/torvalds/linux/blob/master/fs/ocfs2/file.c#L460)
> triggered? (paste log message at the end). I cannot reproduced it so far.
>
> fallocate with FALLOC_FL_KEEP_SIZE flag (man 2 fallocate) can result in
> "le64_to_cpu(fe->i_size) != i_size_read(inode)"
> as explained in this commit message:
>
> ```
> commit d62e74be1270c89fbaf7aada8218bfdf62d00a58
> Author: Younger Liu mailto:younger@huawei.com>>
> Date: Mon Feb 10 14:25:51 2014 -0800
>
> ocfs2: fix issue that ocfs2_setattr() does not deal with
> new_i_size==i_size
>
> The issue scenario is as following:
>
> - Create a small file and fallocate a large disk space for a file with
>FALLOC_FL_KEEP_SIZE option.
>
> - ftruncate the file back to the original size again. but the disk free
>space is not changed back. This is a real bug that be fixed in this
>patch.
>
> In order to solve the issue above, we modified ocfs2_setattr(), if
> attr->ia_size != i_size_read(inode), It calls ocfs2_truncate_file(), and
> truncate disk space to attr->ia_size.
> ```
>
> I was thinking to remove this BUG_ON() assertion. But, the following steps
> cannot
> trigger it:
>
> $dd if=/dev/zero of=/mnt/ocfs2/test2 bs=512 count=1
> $fallocate --keep-size --length 102400 /mnt/ocfs2/test2
> $truncate --size=512 /mnt/ocfs2/test2
>
> I'm wondering why the testing result goes against what I expect? Finally, I
> find that:
>
> ocfs2_inode_lock(inode, bh, 1) in ocfs2_setattr() will update the
> inode->i_size filed from LVB value
> or ocfs2_dinode from disk.
> ---
> vfs_truncate
> do_truncate
> inode_lock()
> notify_change
> ocfs2_setattr
> ocfs2_rw_lock()
> ocfs2_inode_lock()
>ocfs2_truncate_file
> ocfs2_rw_lock()
> ocfs2_inode_unlock
> inode_unlock()
>
> ---
> ocfs2_inode_lock()
> ocfs2_inode_lock_full_nested() ocfs2_inode_lock_update() ==>
> https://github.com/torvalds/linux/blob/master/fs/ocfs2/dlmglue.c#L2204 if
> (ocfs2_meta_lvb_is_trustable()) ocfs2_refresh_inode_from_lvb() else {
> ocfs2_read_inode_block() ocfs2_refresh_inode() } Since we update
> inode->i_size under the protection of thus locks, how was the assertion
> triggered?
> As always, any comments and suggestion will be appreciated!
>
> Thanks,
> Eric
>
> Log message:
> ```
> kernel-default-3.0.101-80
> ocfs2-kmp-default-1.6_3.0.101_68-0.25.6
>
> [239098.534619] (dsmc,8244,6):ocfs2_truncate_file:466 ERROR: bug expression:
> le64_to_cpu(fe->i_size) != i_size_read(inode)
> [239098.534633] (dsmc,8244,6):ocfs2_truncate_file:466 ERROR: Inode 10812,
> inode i_size = 677 != di i_size = 738, i_flags = 0x1
>
> ...
>
> [239098.534724] kernel BUG at
> /usr/src/packages/BUILD/ocfs2-1.6/default/ocfs2/file.c:466!
>
> PID: 8244 TASK: 8801dfb862c0 CPU: 6 COMMAND: "dsmc"
> #0 [8801f59618d0] machine_kexec at 8102c54e
> #1 [8801f5961920] crash_kexec at 810ae858
> #2 [8801f59619f0] oops_end at 8146b558
> #3 [8801f5961a10] do_invalid_op at 810036c4
> #4 [8801f5961ab0] invalid_op at 81472d5b
> [exception RIP: ocfs2_truncate_file+165]
> RIP: a0929ba5 RSP: 8801f5961b68 RFLAGS: 00010296
> RAX: 0085 RBX: 8801dfb862c0 RCX: 7335
> RDX: RSI: 0007 RDI: 0246
> RBP: 1000 R8: 81da3ac0 R9:
> R10: 0003 R11: R12: 8801cbb864f8
> R13: 8801dfb86930 R14: 8801bf5ad000 R15: 02a5
> ORIG_RAX: CS: 0010 SS: 0018
> #5 [8801f5961bd0] ocfs2_setattr at a092c43e [ocfs2]
> #6 [8801f5961c90] notify_change at 8117a0cf
> #7 [8801f5961cf0] do_truncate at 8115e177
> #8 [8801f5961d60] do_last at 8116d0c3
> #9 [8801f5961dc0] path_openat at 8116df29
> #10 [8801f5961e50] do_filp_open at 8116e39c
> #11 [8801f5961f20] do_sys_open at 8115eabf
> #12 [8801f5961f80] system_call_fastpath at 81471d72
> RIP: 7f7da23f67b0 RSP: 7fffae4a3470 RFLAGS: 00010246
> RAX: 0002 RBX: 81471d72 RCX:
> RDX: 01b6 RSI: 0241 RDI: 00cff3df
> RBP: 7fffae4a4ab0 R8: 0004 R9: 0001
> R10: 0241 R11: 0246 R12:
> R13: 00d1d2f0 R14: 00930a68 R15: 0004
> ORIG_RAX: 0002 CS: 0033 SS: 002b
___
Ocfs2
[Ocfs2-devel] BUG_ON(le64_to_cpu(fe->i_size) != i_size_read(inode)) is triggered in ocfs2_truncate_file()
Hi all,
Any one ever see this BUG_ON() assertion
(https://github.com/torvalds/linux/blob/master/fs/ocfs2/file.c#L460)
triggered? (paste log message at the end). I cannot reproduced it so far.
fallocate with FALLOC_FL_KEEP_SIZE flag (man 2 fallocate) can result in
"le64_to_cpu(fe->i_size) != i_size_read(inode)"
as explained in this commit message:
```
commit d62e74be1270c89fbaf7aada8218bfdf62d00a58
Author: Younger Liu mailto:younger@huawei.com>>
Date: Mon Feb 10 14:25:51 2014 -0800
ocfs2: fix issue that ocfs2_setattr() does not deal with new_i_size==i_size
The issue scenario is as following:
- Create a small file and fallocate a large disk space for a file with
FALLOC_FL_KEEP_SIZE option.
- ftruncate the file back to the original size again. but the disk free
space is not changed back. This is a real bug that be fixed in this
patch.
In order to solve the issue above, we modified ocfs2_setattr(), if
attr->ia_size != i_size_read(inode), It calls ocfs2_truncate_file(), and
truncate disk space to attr->ia_size.
```
I was thinking to remove this BUG_ON() assertion. But, the following steps
cannot
trigger it:
$dd if=/dev/zero of=/mnt/ocfs2/test2 bs=512 count=1
$fallocate --keep-size --length 102400 /mnt/ocfs2/test2
$truncate --size=512 /mnt/ocfs2/test2
I'm wondering why the testing result goes against what I expect? Finally, I
find that:
ocfs2_inode_lock(inode, bh, 1) in ocfs2_setattr() will update the inode->i_size
filed from LVB value
or ocfs2_dinode from disk.
---
vfs_truncate
do_truncate
inode_lock()
notify_change
ocfs2_setattr
ocfs2_rw_lock()
ocfs2_inode_lock()
ocfs2_truncate_file
ocfs2_rw_lock()
ocfs2_inode_unlock
inode_unlock()
---
ocfs2_inode_lock()
ocfs2_inode_lock_full_nested() ocfs2_inode_lock_update() ==>
https://github.com/torvalds/linux/blob/master/fs/ocfs2/dlmglue.c#L2204 if
(ocfs2_meta_lvb_is_trustable()) ocfs2_refresh_inode_from_lvb() else {
ocfs2_read_inode_block() ocfs2_refresh_inode() } Since we update inode->i_size under the protection of thus locks, how was the assertion triggered?
As always, any comments and suggestion will be appreciated!
Thanks,
Eric
Log message:
```
kernel-default-3.0.101-80
ocfs2-kmp-default-1.6_3.0.101_68-0.25.6
[239098.534619] (dsmc,8244,6):ocfs2_truncate_file:466 ERROR: bug expression:
le64_to_cpu(fe->i_size) != i_size_read(inode)
[239098.534633] (dsmc,8244,6):ocfs2_truncate_file:466 ERROR: Inode 10812, inode
i_size = 677 != di i_size = 738, i_flags = 0x1
...
[239098.534724] kernel BUG at
/usr/src/packages/BUILD/ocfs2-1.6/default/ocfs2/file.c:466!
PID: 8244 TASK: 8801dfb862c0 CPU: 6 COMMAND: "dsmc"
#0 [8801f59618d0] machine_kexec at 8102c54e
#1 [8801f5961920] crash_kexec at 810ae858
#2 [8801f59619f0] oops_end at 8146b558
#3 [8801f5961a10] do_invalid_op at 810036c4
#4 [8801f5961ab0] invalid_op at 81472d5b
[exception RIP: ocfs2_truncate_file+165]
RIP: a0929ba5 RSP: 8801f5961b68 RFLAGS: 00010296
RAX: 0085 RBX: 8801dfb862c0 RCX: 7335
RDX: RSI: 0007 RDI: 0246
RBP: 1000 R8: 81da3ac0 R9:
R10: 0003 R11: R12: 8801cbb864f8
R13: 8801dfb86930 R14: 8801bf5ad000 R15: 02a5
ORIG_RAX: CS: 0010 SS: 0018
#5 [8801f5961bd0] ocfs2_setattr at a092c43e [ocfs2]
#6 [8801f5961c90] notify_change at 8117a0cf
#7 [8801f5961cf0] do_truncate at 8115e177
#8 [8801f5961d60] do_last at 8116d0c3
#9 [8801f5961dc0] path_openat at 8116df29
#10 [8801f5961e50] do_filp_open at 8116e39c
#11 [8801f5961f20] do_sys_open at 8115eabf
#12 [8801f5961f80] system_call_fastpath at 81471d72
RIP: 7f7da23f67b0 RSP: 7fffae4a3470 RFLAGS: 00010246
RAX: 0002 RBX: 81471d72 RCX:
RDX: 01b6 RSI: 0241 RDI: 00cff3df
RBP: 7fffae4a4ab0 R8: 0004 R9: 0001
R10: 0241 R11: 0246 R12:
R13: 00d1d2f0 R14: 00930a68 R15: 0004
ORIG_RAX: 0002 CS: 0033 SS: 002b
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[Ocfs2-devel] [PATCH] ocfs2: Delete redundant code and set the node bit into maybe_map directly.
The variables set_maybe is redundant while mle had been found in the map. So it
is ok to set the node_idx into mle's maybe_map directly.
This patch is based on linux-4.9-rc2.
Signed-off-by: Guozhonghua
--- ocfs2.orig/dlm/dlmmaster.c 2016-10-28 09:35:55.180696409 +0800
+++ ocfs2/dlm/dlmmaster.c 2016-10-28 09:40:19.020703391 +0800
@@ -1609,8 +1609,6 @@ way_up_top:
__dlm_insert_mle(dlm, mle);
response = DLM_MASTER_RESP_NO;
} else {
- // mlog(0, "mle was found\n");
- set_maybe = 1;
spin_lock(&tmpmle->spinlock);
if (tmpmle->master == dlm->node_num) {
mlog(ML_ERROR, "no lockres, but an mle with this node
as master!\n");
@@ -1625,8 +1623,7 @@ way_up_top:
response = DLM_MASTER_RESP_NO;
} else
response = DLM_MASTER_RESP_MAYBE;
- if (set_maybe)
- set_bit(request->node_idx, tmpmle->maybe_map);
+ set_bit(request->node_idx, tmpmle->maybe_map);
spin_unlock(&tmpmle->spinlock);
}
spin_unlock(&dlm->master_lock);
-
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